The present invention relates to a process for continuously producing roasted cocoa masses or liquor by removing the shells from the raw cocoa beans and crushing the dehulled beans, if desired after a preceding drying and/or fracturing step, in order to produce a more or less thin, liquid cocoa mass and roasting such liquid cocoa mass under atmospheric or reduced pressure while moving the cocoa mass and heating it to a maximum temperature of about 150.degree.C through indirect heat transfer by means of heating surface.
Conventionally, whole or merely roughly fractured cocoa beans are used almost exclusively for the so called roasting of cocoa, that is, the cocoa beans are heated for a certain length of time to temperatures of up to about 150.degree.C although it has been recognized long ago that in these roasting processes, including the so called fractured bean roasting, over and/or under roasting cannot be avoided due to the fact that the particles to be roasted have a relatively large size or diameter which causes a temperature drop between the surface of the particles to be roasted and their inner portions. As a result, the roasting cannot be accomplished in a uniform manner. The just described problem was clearly recognized more than half a century ago, even as to its causes, for example, by German Patent 297,888 which discloses in its basic technical teaching a presumably correct suggestion for solving the above problem. German Patent 297,888 teaches to crush the dehulled raw cocoa beans to form a pulpy or liquid mass and to spread it in this form as a thin layer onto smooth moving surfaces which are heated to the roasting temperature of about 100.degree.C to 150.degree.C.
Further developments and modifications of the above teaching have become known in the meantime, for example according to French Patent 175,347 which suggests to perform the roasting under normal atmospheric pressure or under reduced pressure in double walled roasting chambers which are provided with stirring means. Yet another proposal has been disclosed in German Patent Publication 1,919,870 which suggests performing the roasting of the cocoa liquid while stirring it under increased above atmospheric pressure and to eject the roasted cocoa mass into a ventilated collecting chamber in order to remove undesired volatile components which resulted from the roasting or which have been liberated by the roasting.
In spite of the just outlined developments and in spite of the fact that the roasting methods which are employed to this day in the industrial practice have basic disadvantages, especially that of an uneven roasting result, the teaching disclosed by said German Patent 297,888; namely to roast the cocoa in the form of crushed, raw cocoa beans having a pulpy or liquid cocoa mass consistency, has not found any substantial practical application either in its originally disclosed form nor in any of the subsequent modifications or developments. In fact, as far as applicants know, such teaching has not even been accepted to a limited extent in the present day practice. This fact shows clearly and surprisingly, that the problems which occur in the roasting of cocoa with regard to the uniformity and quality of the roasted product, can not be solved solely by the means disclosed in the above discussed three patents.
The roasting of the raw cocoa beans and the so called conching of the chocolate mass play a substantial roll in the production of chocolate, especially with regard to the quality of the end product as far as its aroma and its taste characteristics are concerned. The conching is a rather time-consuming process which, as a rule, requires between about 12 and 78 hours. Further, the conching cannot be performed on a continuous basis. Therefore, the chocolate industry has been searching for some time now and with substantial efforts and expenditure for possibilities which would permit to either substantially reduce the conching or to avoid it altogether. For example, in connection with the above mentioned German Patent Publication 1,919,870 it was believed that the just mentioned problem of shortening or eliminating the conching could be solved by way of a special roasting of the cocoa in a manner which basically has been known for a long time. However, as mentioned above with reference to German Patent 297,888 and with reference to French Patent 715,347 the prior art has so far not been successful in eliminating or reducing the required conching. This applies also with regard to the German Patent Publication 1,919,870 since experiments have in the meantime shown that the resulting products still require some conching where high quality chocolate is to be obtained.